Medical Dressing with Semiconducting Polymer Dots for Photocatalytic Hydrogen Evolution and Diabetic Wound Healing

Impaired wound healing is the most common and severe complication in diabetic patients. Here, we develop a new type of medical dressing for diabetic wound healing by using photocatalytic hydrogen evolution from semiconducting polymer dots (Pdots) under red-light irradiation. The Pdots consist of semiconducting polymer (PM6) and fullerene derivative (PCBM), forming a donor-acceptor heterojunction structure with efficient photocatalytic hydrogen evolution. The antioxidant capacity of the heterojunction Pdots by PM6:PCBM was characterized to be ∼2.5 times higher than that of the donor-acceptor Pdots species in previous studies. By directly loading the heterojunction Pdots into a sterile medical dressing, we show that the medical dressing effectively scavenges hydroxyl radicals in diabetic wounds, promotes the expression of anti-inflammatory cytokines, and accelerates wound healing under low-dose red-light illumination. We analyze immunofluorescence staining of the skin tissues and discovered the effect of hydrogen therapy on an inflammatory process such as macrophage polarization from M1 type to M2 type. This study highlights the efficient hydrogen generation from Pdot-loaded medical dressing, providing a new approach for treatment of diabetic wounds.